It is generally understood in the industry that the performance of a golf club head is largely dependent on the location of the Center of Gravity (CG) and Moment of Inertia (MOI) of the golf club head. In order to adjust the CG and MOI of a golf club head, golf club designers often strategically place mass at specific locations within the golf club head to achieve the desired CG and MOI. Pursuant to the design objective above, golf club designers have constantly struggled with ways to reduce unnecessary mass from various portions of the golf club in order to strategically place it at more desirable portions. This process is so important to the design of a golf clubs; the golf club design industry even has a specific term used to describe this type of mass savings, called “discretionary mass”.
U.S. Pat. No. 6,152,833 to Werner et al. illustrates one of the earlier examples of trying to create more discretionary mass by creating a lightweight low density striking face that is supported to its rear by a hollow shell structure.
U.S. Pat. No. 6,860,824 to Evans illustrates another example of golf club designers attempt in creating more discretionary mass. In U.S. Pat. No. 6,860,824 it is contemplated that a golf club head has a body portion that is preferably composed of a lightweight non-metallic material to help reduce mass from the body portion of the golf club head.
U.S. Pat. No. 5,624,331 to Lo et al. illustrates another example of increasing discretionary mass by creating a composite-metal wood-style golf club head having a metal casing with at least two openings in the crown in which composite covers are disposed.
Finally, U.S. Pat. No. 7,361,100 to Morales et al. illustrates a modern day example of utilizing modern day materials to increase the discretionary mass within a golf club. More specifically, U.S. Pat. No. 7,361,100 discloses a golf club head that is formed with a crown having an aperture with an arcuate rear edge and a forward edge that is substantially parallel to the striking face, wherein the opening formed in the aperture by the ribs are filled with an organic-composite material such as carbon fiber epoxy.
It should be noted that although all of the above referenced prior art are very capable of reducing unnecessary mass from various portions of the golf club head, it fails to address the ancillary drawback associated with the usage of lightweight materials such as graphite composite. When lightweight materials are used to replace metallic materials at various portions of the golf club, the sound and feel of the golf club can significantly degrade, resulting in a undesirable golf club. Hence it can be seen from the above that although the current art is capable of creating discretionary mass by using lightweight materials, it fails to do so while minimizing the undesirable sound and feel of the golf club.